There has been conventionally a diaphragm pump which is, for example, shown in FIG. 44, as an electromagnetic vibrational diaphragm pump sucking and discharging fluid utilizing the vibration of a vibrator which was equipped with a magnet based on electromagnetic interaction between an electromagnet and said magnet.
The pump is composed of an electromagnet portion 151 having an electromagnet 151c consisting of an iron core 151a provided in a frame 150 and a winding coil portion 151b, a vibrator 153 equipped with a magnet 152 which is arranged at a gap portion of said electromagnet, diaphragms 154 connected with both ends of said vibrator 153, and pump casing portions 155 respectively fixed on both end portions of the above-mentioned electromagnet portion.
In such pump, air sucked from a suction inlet 156 by the left and right vibrations of the above-mentioned vibrator 153 was once stored in the suction tank portion 157 of the above-mentioned electromagnet portion 151, then once stored in a discharge tank portion 161 through the suction chamber 158 of the pump casing portions 155, a pump chamber (compression chamber) 159 and a discharge chamber 160, and then discharged from a discharge portion 162.
However, the structure of a conventional diaphragm pump can generate only a low pressure of less than 50 kPa, therefore there is a problem that it is difficult to generate medium pressure (about 50 to 200 kPa). To the contrary, although a piston type pump can generate medium pressure, there are problems that life time is shorter than a diaphragm pump because of the abrasion of a piston and efficiency is low.
Further, it is also desired to make a diaphragm pump in a small size.